Health officials in Ontario have recorded the first death of a person with a rare blood clot who received a dose of the AstraZeneca COVID-19 vaccine in April.

Associate Chief Medical Officer of Health Dr. Barbara Yaffe confirmed the news during the province’s bi-weekly update on its COVID-19 response Tuesday.

“Unfortunately, I must report that we now in Ontario have our first death associated with VITT (vaccine-induced immune thrombotic thrombocytopenia),” Yaffe said.

She said the man in his 40s received his first dose of the AstraZeneca vaccine “toward the end of April” and died a “few weeks later.”

Yaffe explained that while an investigation into the man’s death is ongoing and the final cause of death has yet to be officially determined, it has been confirmed that he had VITT at the time of his death.

Earlier this month, Ontario announced that it would no longer offer first doses of the AstraZeneca COVID-19 vaccine due to an increase in reports of rare, but potentially fatal, blood clots.

At that time, Chief Health Protection and Emergency Preparedness Officer Dr. Jessica Hopkins said the risk of VITT associated with the vaccine in Ontario was one in 60,000.

On Friday, the province said it would resume use of the vaccine, but only as a second dose, as it rushes to use tens of thousands of shots before they expire on May 31.

Yaffe said that Ontario has a total of 16 cases of thrombotic thrombocytopenia, of which 13 cases now meet the criteria for VITT.

No other details regarding the deceased person have been released.